1. Field of the Invention
The invention relates to a process and device for adjusting a movable motor vehicle part between at least two positions by means of a drive.
2. Description of Related Art
The prior art discloses various possibilities for detecting and prevent pinching of an article or body part, for example, by an openable motor vehicle roof, etc.
Thus, it is known, for example, that pinch protection can be accomplished for adjustable covers of an openable motor vehicle roof by monitoring the operating parameters of the cover drive motor. Here, the motor current, its change over time, or the torque of the drive motor can be monitored; see, for example, published German Patent Applications DE 198 40 161 A1, DE 198 40 162 A1, DE 198 40 163 A1, and DE 198 40 164 A1 and its counterpart U.S. Pat. No. 6,753,676, German Patent DE 33 29 986 C2, published German Patent Application DE 196 18 219 A1, and its counterpart U.S. Pat. No. 6,070,116 and German Patent DE 195 07 541 C1 and its counterpart U.S. Pat. No. 5,764,008.
Furthermore, anti-pinching devices for an adjustable cover of an openable motor vehicle roof are known, for example, from published German Patent Applications DE 37 31 428 A1 and DE 195 35 796 A1 and German Patent DE 197 50 711 C2 and its counterpart U.S. Pat. No. 6,076,886, in which pinch sensors are mounted on the front edge of the cover or the front edge of the roof opening, and can be formed, for example, as piezoelectric pressure sensors in the form of optical fibers or as FSR sensor elements which change their resistance under pressure. Since these sensors must be provided over the entire width of the roof opening to accomplish effective pinching protection, this pinch protection is very complex and expensive.
The above described anti-pinching systems have the disadvantage that they only react when clamping forces occur. In doing so, as a result of the great inert masses, large pinching forces occur until the drive stops so that the pinched object is first exposed to greater forces.
Published German Patent Application DE 198 16 054 A1 describes a camera system for monitoring the motor vehicle vicinity which cannot be directly viewed, in which the camera can be adjusted in two working positions with different focal widths and angles to the roadway. The cameras of the camera system are distributed over the motor vehicle. Furthermore, there is a display device which displays to the driver the images recorded by the camera.
Published German Patent Application DE 199 20 090 A1 describes an electronic passenger car parking aid which facilitates parking next to the curb and warns against contact with it. In doing so, ultrasonic sensors on the front and back in the area of the bumpers are mounted on the motor vehicle and face the roadway at different angles. When parking, the sensor field is penetrated and a signal sounds.
Published German Patent Application DE 199 31 014 A1 discloses a distance sensor for a motor vehicle which covers at least the entire side area of the motor vehicle. A laser scanner is used which is located in the mirror joint, in the outside mirror or in the mirror housing itself.
Published German Patent Application DE 143 099 A1 describes a process for monitoring the rear area of the motor vehicle. In doing so, the side rearview mirror of the motor vehicle is replaced by a video camera which allows at least two different imaging scales for different image angles. The different pictures are displayed to the driver in succession on one or at the same time on two monitors.